Mandrel for sound-records.



F. L. GAPPS.

MANDREL FOR SOUND REGGRDS.

APPLICATION FILED SEPTA, 1913 Patented Dec. l, 1.9i@

m 19mg@ \i GK *i wifi/zone ITE VIRGINIA.

MANEPUEL EUR El Application filed September l,

Be it known that l, FRANK L. Cares, of Bridgeport, Connecticut, have invented a new and useful Improvement in Mandrels for Sound-Records, which invention is fully setlorth lin the following specification.

This invention relates to talking inachines, and more particularly to mandreis employedin such machines for supporting and revolving;` `the records. lt is usual to make such records with a cylindrical este rior surface and a slightly conical shaped interior, to the end that the records may be slipped onto a tapering or slightly conical mandrel. The interior dimensions of the records and the exterior' dimensions 'of the mandrel will vary slightly, either through variations in the manufacture, or by reason of the fact that they expand and contract under changing degrees of temperature; but the conical or tapering shape ol the mandrel and thc corresponding shape oi' the interior ot' the record enable the record to bc pushed far enough on the mandrel to the same and engage it with suilicient friov tion to enable it to loe driven thereby= Bat if the mandrel is slightly larger or smal than the standard; if the record slightly larger or smaller than the sizes; or if the mandrel and record exactly of the standard size at one ture, and their dimensions have been Varied by reason of changes of temperature, the record when placed upon the mandrel will not always occupy exactly the same posits-n longitudinally of the mandrel. A large ri ord will be slipped farther upon a given mandrel than a small record, and a record will be slipped farther onto the drcl when the parts are exwninded hy temperature than would be the case wf low temperature. Moreover, thev standard mandrels are made oiE metal, andthe cow elicient of expansion and contraction'ii-il' the metal differs from that of the wax or Vaxlike material of which the record is made, and if the record. is left upon the mandrel under a high degree of temperature, and the temperature then falls, the contraction of the record being` greater than that of the 'mandreh the record will be split and destroyed. Again, even in carefully construct ed machines,the vibrations of the machine are transmittedthrough the mandrel to the Moord. which introduces more or less ina-c- Specicaton of Letters Patent.

records and with vary so anestesia citarnea cosronarifna' or weer cnracy in. the action or" the'niaehine, either inrecordingor in reproducing.

vThe matter of varying positions of the .record upon the mandrel is one of marked importance in some classes of machines, s uch for exan'iple. yas those used for dicta tion pi poses, wherein correction devices are employed, in which the position of the record with relation to the correction 4device plays an important part., and it has therefore been found desirableto provide a, fixed stop against which the record is ahatted at one end, to exactly and accuratelydeterznine its position enI all machines. lil/ith a metallic mandrel, this et:- act positiiinconld not he obtained with all 4degrees of tempeinture, for the reasons indicated' above. Furtlmrmore, it is desirable to provide some means tor starting tl loose from the mandrel when the san... is to be removed, and such means generally occnp lined position apen the 1"lachine, an a 'variation in the 'oesitiin of the r1 nnlitates agfains such loosen' e el the ooge. o i ,lesensnnen tore.

,c mandrel ier acoustiirorn the aie-.n-

. aiiating the noord invention mandrel, i of iengi -'ly extend seine yielding material, which will acoustically insulate the metal of the mandrel from 'the record. The ribs must be ol a material which Will not only all'ord the acoustic insnlation desired, but which will allord a secure hold upon the interior of the record, so as to cause to revolve with the mandrel without any slipping, and which, nevertheless, will. yield snll'ieiently to enable the mandrel to compress it to a material extent, to en able each and every record to be forced onto the mandrel to the exact position required. l have discovered that a compact felt is a most excellent material from which to con on in:

struct 'said ribs. The felt alords a firm grip on the interior of the record; it acoustically insulates the record from the metal mandrel; and when in the form of ribs, it yields sullciently to enable the record, even though of slightly diminished interior diameter, to be forced home to the desired position. I give the yfelt or other similar yielding material theform of ribs, since the material, when formed in the shape ofr long narrow strips orribs, will yield much more readily than would be the case if an entire cylinder of felt or other similar material surrounded the mandrel. The ribs expand laterally under the pressure of the record, whereas if an entire cylinder or coating of yielding material were employed, it would simply be compacted by the record when :forced thereon. This would result in a much less desirable and less flexible element, and atan increased cost, since it would involve the use of more than double the amount o material.

The invention will be best understood by reference to the accompanying.drawings, which illustrate one expression of the inventiveidea, and in which-` L Figure l is a perspective view; Fig. 2 1s a crosssection on the line 2-2 of Fig. 3; and Fig. Sis a longitudinal section on the line 3-3 of Fig. l. l

Referring to the drawings, wherein like reference numerals indicate like parts, 4 is a tapering metallic mandrel, the outer surface of which is provided with projections a, preferably in the form of equally spaced longitudinal ribs of yielding, acoustically insulating material, such as a well-'compacted felt. Such ribs are secured to the mandrel in any desired manner, preferably by means of cement, andit1 desired, may be located in depressions or recesses (3 provided in thc mandrel r he mandrel -l is preferably provided with a plurality 'of slots T in each of which a linger 8. forming part of an cjecting,r device, is located,- said fingers S having longitudinal movement from left to right impart ed thereto upon the rotation of a turn screw 9 operatingthrough suitable mechanism, not shown. This construction is not claimed herein, since the same Vlforms the-subjectinatter ot' a separate application filed ot' even date herewith. Further, the mandrel l is preferably provided at its inner lei`t-hand end with an outwardly projecting liange 9', to which is secured a body l0 of yielding, acousticallv insulating material, preferably oi the same felt which constitutes the ribs 5. l

This body or ring l0 of felt is interposed between the ends of the ribs 5 and the flange 9', and when the tablet is in position on the mandrel, the inner end of the tablet bears against the ring l0, which thus serves to exactly position the record tablet longitudinally ofthe mandrel.

It will be observed that if a record tablet whose internal diameter was slightly less than the standard were placed upon the mandrel, the ribs 5 would yield laterally when the tablet was forced home, thus permitting the tablet to be forced snugly against the stop composed of the felt ring l0, and this position would enable the ejecting device to operate thereon with certainty; would enable the correction device to occupy its proper relation thereto :-and all Without imposing any undue strain upon the record. either in placing it upon the mandrel or in case oi' exliansion and contraction, due to changes in temperature. In addition to this, the record would always be acoustically insulated from the metal of the mandrel.

The inventive idea issusceptible of various .mechanical expressions, the limits of the invention being defined in the appended claims.

What is claimed is I l. A tapering mandrel for sound records provided with longitudinally extending spaced projections of a yielding, acoustically insulating material.

A tapering mandrel for sound records provided with longitudinal ribs of felt extending above the surface thereof.

il. A tapering metallic mandrel for sound records provided with longitudinal ribs of l'elt held in depressions in said mandrel and extending above the surface thereof.

a. A tapering metallic mandrel for sound records provided with an outwardly extending llange. ribs of felt arranged longitudi nally of said mandrel and extending above the surface thereof, and a body of yielding sound insulating material arranged between said ribs and said flange.

5. tapering metallic-mandrel for sound records provided with an outwardly extending llange. rios of 'felt arranged longitudinally ol" said mandrel and extending above the surface thereof, and a body of felt arranged between said ribs and said flange.

.i taperingr metallic mandrel for sound records provided with longitudinal ribs of l'elt held in depressions in lsaid mandrel and extending above the surface thereof and having an end stop of yielding material for said records.

ln testimony whereof I have signed. this Vspecification in the presence of two subscribing witnesses.

FRANK L. CAPPS.

Witnesses:

donn S. GRIFFITH, L. S. EASTMAN. 

